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Particles without a Box: Brush-first Synthesis of Photodegradable PEG Star Polymers under Ambient Conditions
Published on: October 10, 2013
Supramolecular Helical Miktoarm Star Polymers
Ru Deng1, Chengyuan Wang1, Marcus Weck1
1Department of Chemistry and Molecular Design Institute, New York University, New York, New York 10003, United States.
Abstract:
We report a hydrogen-bonded supramolecular miktoarm star polymer containing three distinct helical arms. Our design involves two helical poly(methacrylamide) arms connected by a barbituric acid (Ba) at the center, prepared through the reversible addition-fragmentation chain-transfer polymerization with a bifunctional agent. Together with a telechelic helical poly(isocyanide) end-functionalized with a Hamilton Wedge (HW) that is complementary to Ba, the two components assemble into an AB2-type star copolymer. The assembly is driven by the hydrogen bonding between HW and Ba, which is quantified by 1H NMR titration and isothermal titration calorimetry. Gel-permeation chromatography provides evidence for the formation of the desired miktoarm star architecture. This strategy of site-specific functionalization on helical polymers provides a modular approach to preparing nonlinear supramolecular ensembles with topologically diverse building blocks.
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